U.S. Pat. No. 3,459,466 issued to J. A. Giordmaine on Aug. 5, 1969 describes an optical beam peak power amplifier and buncher.
Essentially, this patent teaches the concept of breaking up a light beam into spatially separated portions and thence subjecting the spatially separated portions to different delay times so that the same can be reassembled to all occur substantially at a single moment in time.
In my U.S. Pat. No. 3,684,346 issued Aug. 15, 1972 there is described an optical integrating system which accomplishes an integration of spatially and time separated light pulses into a single large pulse of light by utilizing a unique arrangement of fiber optics together with a special reflective crystal capable of generating progressively increasing annular rings of light.
In both of the foregoing systems, there is involved a "fly back" time in the scanning of the initial light beam in order to "break up" in a time and spatial sequence the light involved so that successive portions thereof can be delayed in such a manner that they will all add up at the output. For example, if a row of delay lines is provided, the light will successively impinge on the inlet ends of the delay lines until it reaches the last of the delay lines and then the light must be returned to its initial position; that is, scan back quickly to the first one of the delay lines and the process then repeated.
The same situation obtains in my above-mentioned U.S. patent wherein concentric rings of light are employed in the scanning operation. When the last or largest diameter ring is completed, the generating crystal must return to its initial state to commence a second succession of ever-expanding rings of light and it is during the return time that the light is wasted.
In my presently pending United States patent application Ser. No. 185,144 filed Sept. 8, 1980 and entitled Annular Scanning Light Pulse System, there is disclosed an improved apparatus for converting light into one or more output pulses of very high amplitude utilizing the principles set forth in the prior mentioned U.S. Patents but wherein there is no loss of light during any "flyback" time.
The foregoing is achieved by providing a series of light paths having individual light entrance ends and light exit ends, the light entrance ends being arranged in an annular or circular array. The lengths of the paths successively decrease from one path to the next adjacent path until the shortest path is reached which shortest path is immediately followed by the path of greatest length. A means for cylically sweeping a light beam such as a laser beam in a circular pattern is provided so that the angularly arranged light entrance ends of the paths can be sequentially scanned and in a cyclical or continuous manner over 360.degree..
The time for light to travel the difference between successive path lengths corresponds to the time of scan of the light beam from one light entrance opening or end to the next successive light entrance opening or end so that light passes from the light exit ends of the various light paths substantially simultaneously Because of the annular or circular sweep pattern for the light beam, there is not involved any "flyback" time so that the maximum use is made of the initial light.
The success of my above-described system resides in being able to provide a mechanical means for causing the laser beam to scan a circular pattern at an extremely high frequency. While it is possible to provide extremely high speed motors for effecting the necessary scanning operation, an improvement could be achieved if other type scanning not involving mechanically moving parts could be realized.